Tanstein Castle is one of the three castles at Dahn; the others being Altdahn and Grafendahn. Although the three castles are sited next to one another on a hill ridge, they were not built at the same time.
Tanstein is the oldest of the three castles in the group. An 1127 document refers to an Anshelmus de Tannicka as the owner or governor; as a result the castle was probably built in the early 12th century. In 1189, in a deed by Emperor Frederick Barbarossa, a Henry von der Than is mentioned and the castle designated as an immediate imperial fief. In the period that followed, Ulrich of Dahn and Conrad of Dahn are named as imperial ministeriales. In 1328 the castle became a fief of the bishops of Speyer. Until 1464 there were frequent changes of ownership, which suggests that the fief was still not inheritable during this phase, but was always re-enfeoffed.
In 1512 Frederick of Dahn purchased the castle. Because he was an ally of the knight, Franz von Sickingen, he was involved in his battles against the imperial princes in southwest Germany. After Sickingen's defeat and death in 1523, Tanstein, too, fell into the hands of the victors. Its occupation by troops of the Archbishop of Trier lasted until 1544 and probably led to irreparable damage to the structure of the castle, because it was finally abandoned in 1585. In 1689, at the start of the War of the Palatine Succession, the French completely destroyed the ruins.
Tanstein Castle is located on the two westernmost rock outcrops of the Dahn castle cluster. Both were originally linked by a bridge. On the rocks today are modern parapet walls that have been rather arbitrarily added and do not give any real idea of the old castle buildings. On the western rock outcrop there were apparently domestic-like buildings, that were built against the rocks. This is evinced by putlock holes and other marks on the rocks as well as a large cistern, in which water from the roofs was gathered and stored.
The lower ward on the southern rock outcrop still shows traces of the original walls dating to the 15th century. These include the ruins of a smithy and a smelting furnace.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.